The Pro150's 230 Isp was obtained with the conventional nozzle and an operating Pc of about 495 Psi. The aerospike version uses a different propellant system to optimize aerospike dynamics. Conventional solid propellant formulations can reduce the ultimate performance of an optimized aerospike. The Pro150 has a 225mm big brother (AWSRM booster) that uses a composite case and an IM spec. propellant. It has a demonstrated Isp of over 232. If you go to the CTI web site under the news section, you can download a video of a test. Ignition time is less than 100 milliseconds. There is also a video of a flight test with the smaller booster down the page.
These systems are engineered for reliability and repeatability over a wide range of temperatures, conditions as well as storage life, so ultimate Isp is not necessarily the ultimate goal. Higher impulses are not unusual in military systems without getting too exotic.
Some advanced propellants we've worked on (HNF/PolyNIMMO) deliver over 270 seconds without any metal. Loud as hell but no smoke and very little visible flame. Over $10,000 a pound to boot. Military research application and it goes like stink. Perfect for an E or F-1000 model rocket motor.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
https://www.cesaronitech.com/
(905) 887-2370 x222 Toronto
(410) 571-8292 Annapolis